The present invention is directed to a sealed electrical assembly, more specifically, to an electrical assembly having a cover with tab portions spaced apart from a back surface of the cover to facilitate sealing of the electrical assembly.
Electrical assemblies are packaged in a wide variety of different housing assemblies. Referring to FIG. 1, one type of prior art housing assembly includes a housing 1 with an open end 2 and a cover 3 with tabs 4 that snap into cutouts 5 in the housing to secure the cover to the housing. One advantage of the type of housing assembly illustrated by FIG. 1 is that it is very easy to put together. One disadvantage of the type of assembly illustrated by FIG. 1 is that water can easily migrate past the cover 3 or through the cutouts 5 into the housing assembly and damage the enclosed electronics.
A variety of sealed housing assemblies are available. One type of sealed housing assembly includes a housing and a cover that is welded to the housing. Welded housing assemblies are expensive to assemble because the welding operation is difficult and time consuming.
Potting material has been used to seal electrical assemblies. In traditional potted housing assemblies, potting material is dispensed into the housing to seal the enclosed electronics. A cover may be placed over the potting or the potting material may be used in lieu of a cover. One disadvantage of a traditional potted housing assembly is that the electrical parts enclosed in the housing assembly are covered with the potting material. Once the parts are covered with the potting material the parts cannot be visually inspected. In the case of an electrical assembly that includes a display, such as a meter, it is particularly undesirable to contact the viewed surface of the display with potting and conceal a portion of the display.
There is a need for a sealed housing assembly that is easy to put together. Further, there is a need for a sealed housing assembly that allows the electrical components to be visually inspected after the housing assembly is sealed. There is also a need for a sealed meter housing assembly that prevents potting from contacting the display.
The present invention is directed to a sealed electrical assembly. The electrical assembly includes a housing having an opening at one end. An electrical device is positioned in the housing. The electrical device includes a lead that extends out of the open end of the housing. A cover is positioned within the opening of the housing. The cover includes a plate portion and a tab portion spaced apart from the plate portion. The tab portion extends into a cutout in the housing and is located between the plate portion and the housing end. The tab in the cutout positions the cover with respect to the housing. A sealant is applied to an outer surface of the cover such that sealant is disposed around the perimeter of the plate portion. The sealant provides a seal between the cover and the housing. A portion of the sealant is disposed in a space between the tab portion and the plate portion of the cover, such that fluid is prevented from migrating into the housing through the cutout.
In one embodiment, the electrical assembly is a sealed visible meter assembly, such as hour meter for a lawn and garden tractor. In this embodiment, the housing is transparent with a front wall and four side walls. A meter circuit including a display is positioned in the housing, such that the display is visible through the transparent front wall of the housing. Leads of the metering circuit extend out of the open end of the housing. The cover includes a plate portion, a pair of wings extending away from the surface of the plate portion and a pair of rectangular tab portions that extend from the wing portions. The tabs extend into a pair of cutouts in the side wall of the housing to position the cover with respect to the housing. Sealant, such as a potting material, is disposed on the cover to provide a seal between the cover and the housing. The sealant may be disposed around the leads to provide a seal around the leads.
The housing may include latching projections that facilitate mounting of the housing to a panel. These projections facilitate a snap-in mounting of the housing assembly to a panel. In one embodiment, the latching projections facilitate mounting of the housing to a panel from the front. In one embodiment, the latching projections facilitate mounting of the housing assembly to a panel from the rear.
In one method of sealing an electrical housing assembly, an electrical device is positioned in the housing such that a lead of the electrical device extends out of the open end. A cover including plate portion and tab portion spaced apart from the plate portion is positioned in the housing. The tab portion is inserted into a cutout in the housing that is located between the plate portion and the housing end. A sealant is applied to the cover, such that sealant is disposed around the perimeter of the plate portion. The sealant provides a seal between the cover and the housing. A portion of the sealant is applied in a space between the tab portion and the plate portion to prevent fluid from migrating through the cutout into the housing.
The housing assembly of the present invention is sealed and is easy to put together. Another advantage of the housing assembly of the present invention is that the electrical components enclosed in the housing can be visually inspected after the housing assembly is sealed when the housing is made from a transparent material. The housing assembly of the present invention prevents a sealant or potting from contacting the electrical components in the housing, such as a display.
These and other objects, advantages and features of the invention will become better understood from a detailed description of an exemplary embodiment of the invention which is described in conjunction with the accompanying drawings.